Ofcom has launched an investigation into whether BT has an unfair market advantage in the UK fibre broadband sector.
Responding to a complaint made by rival broadband provider TalkTalk, the media regulator is to consider the level of competition in the burgeoning industry, reports ISPreview.co.uk.
TalkTalk has repeatedly raised concerns about BT's positioning in the UK broadband sector and the absence of effective industry regulation.
However, BT - which makes its network infrastructure available to other operators on a wholesale basis - has staunchly defended its position.
Last month, BT's Chief Executive Ian Livingston told the Telegraph that certain providers were "trying to stop the fibre programme so they can sweat their own copper assets".
In a statement, Ofcom acknowledged receiving a complaint from TalkTalk over BT's "dominant position" in the market.
"Specifically, TalkTalk Group alleges that BT has failed to maintain a sufficient margin between its upstream costs and downstream prices, thereby operating an abusive margin squeeze," the regulator stated.
"Ofcom has now opened an investigation into the matters raised by TalkTalk Group's complaint and will consider whether BT has abused a dominant position under UK and/or EU competition law."